Lewis was cut by the 49ers on Oct. 1 after skipping a practice and a road trip, reacting to the news that he had lost his starting job to rookie Taylor Mays. Lewis is a nine-year veteran.
After practice Wednesday, Rams coach Steve Spagnuolo wasn't sure if Lewis could be ready in time for Sunday's game against the Carolina Panthers. The Rams have two healthy safeties, with James Butler hindered by a knee injury that likely will sideline him this week and Darian Stewart hampered by a hamstring injury.
Lewis played for the Philadelphia Eagles when Spagnuolo was the team's defensive coordinator.
Defensive tackle Clifton Ryan, bothered most of the year by migraine headaches, was placed on season-ending injured reserve.
Copyright 2010 by The Associated Press